The state of Washington has several volcanoes which are classified as active. Of these,
most recent volcanic eruption occurred from Mount Saint Helens between 2004 and 2008. However,
this is not the only volcano which could erupt again in the near future. In northern Washington,
there exists another volcano which erupted more than a dozen times in the 19th century.
The volcano I am referring to is Mount Baker, which last erupted in 1880.
This video will discuss this active volcano, and mention what its future hazards are.
The region around Mount Baker is very geologically active and has produced numerous volcanic centers
in the past several million years. However, the base of what is now Mount Baker did not
truly start to form until 495,000 years ago. The initial phase of volcanic activity was
marked by the eruption of Black Buttes. Over the next several hundred thousand years, eruption
after eruption of andesite lava built a tall stratovolcano. During the same period of time,
this volcano produced several other volcanic cones. One of these cones erupted to the northeast
between 460,000 and 296,000 years ago, and formed the area now known as the "Lava Divide".
The last eruption from Black Butte occurred 288,000 years ago,
after which the volcano became largely dormant. The next period of volcanic activity began
140,000 years ago, and occurred on top of previous lava flows from the Black Buttes.
However, these eruptions did not truly start to add to the height of Mount Baker until 30,000
years ago, when a major period of cone growth began. For the next several thousand years,
more than 100 explosive and effusive occurred and created an ever increasing peak.
One interesting eruption occurred 5 miles south of the main summit 9900 years ago.
This eruption formed a low prominence cinder cone known as the Schreibers Meadow cone. This vent
produced a several mile long lava flow, which flowed all the way to what is now Baker Lake.
The next eruption occurred in 4550 BC at Sherman Crater on the main summit. What started as a
series of hydrothermal explosions turned into a major explosive eruption. This subplinian
eruption created a series of pyroclastic flows which raced down the mountain and caused a layer
of ash to fall up to 41 miles away. Additionally, this eruption created two lahars. One went to the
east where it damned the river to form Baker Lake. The other went to the west, and traveled down the
Nooksack River. This lahar was several hundred feet high and traveled more than 40 miles away.
No additional volcanic activity was recorded at Mount Baker until 1820, when a phreatic eruption
occurred on the summit. An eruption an order of magnitude larger occurred several decades
later in 1843, which also generated a lahar. From 1846 until 1884, as many as 15 additional
small phreatic eruptions occurred at this volcano. Since then, no additional eruptions have occurred.
So, what hazards could Mount Baker pose, and how dangerous is this volcano?
The US Geological Survey recently designated Mount Baker as a very high threat volcano.
Within the state of Washington, it has erupted only slightly less in recent history than Mount
Saint Helens and Mount Rainier. The reason why Mount Baker is considered high threat is due to
its history of long distance and destructive lahars. To understand what a lahar is,
picture a 100 foot tall flash flood coming towards you where the water is filled with rocks,
mud, ash, and trees. Lahars can form in a number of ways such as landslides, although they most
frequently form when a volcanic eruption melts a portion of snow on top of the mountain. A
future lahar could reach more than fifty miles away, and affect a number of towns which exist
on low lying areas. The map shown on screen shows what a worst case scenario lahar would reach.
A future eruption could also create pyroclastic flows and lava flows,
although these two hazards are unlikely to travel more than 5 miles from the summit.
Overall, I predict the next eruption to be a phreatic eruption, and put the odds of an
eruption at about 1 in 250 each year. I hope that you enjoyed this video! If
you would like to request a specific topic, please leave a comment below.